<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar 
      class="app-nav-bar"
      title="文章详情"
      left-arrow
      @click-left="$router.back()"
    />
    <!-- /导航栏 -->

    <div class="article-wrap">
      <h1 class="title">{{article.title}}</h1>
      <van-cell center class="user-info">
        <div slot="title" class="name">{{article.aut_name}}</div>
        <van-image 
          slot="icon"
          class="avatar"
          round
          fit="cover"
          :src="article.aut_photo"
        />
        <div slot="label" class="pubdate">{{article.pubdate|relativeTime}}</div>
        <van-button
          class="follow-btn"
          :type="article.is_followed ? 'default':'info'"
          :icon="article.is_followed ? '':'plus'"
          round
          size="small"
          :loading="isFollowLoading"
          @click="onFollow"
        >{{article.is_followed ? '已关注':'关注'}}</van-button>
      </van-cell>
      <div class="markdown-body" ref="article-content" v-html="article.content">
      </div>
      <!-- 文章评论列表 -->
      <comment-list 
        :source="articleId" 
        :list="commentList" 
        @update-total-count="totalCommentCount = $event"
        @reply-click="onReplyClick"
      />
      <!-- /文章评论列表 -->
    </div>

     <!-- 底部区域 -->
    <div class="article-bottom">
      <van-button
        class="comment-btn"
        type="default"
        round
        size="small"
        @click="isPostShow=true"
      >写评论</van-button>
      <van-icon
        name="comment-o"
        :info="totalCommentCount"
        color="#777"
      />
      <van-icon
        :color="article.is_collected ? 'orange' : '#777'"
        :name="article.is_collected ? 'star' : 'star-o'"
        @click="onCollect"
      />
      <van-icon
        :color="article.attitude === 1 ? 'hotpink' : '#777'"
        :name="article.attitude === 1 ? 'good-job' : 'good-job-o'"
        @click="onLike"
      />
      <van-icon name="share" color="#777777"></van-icon>
    </div>
    <!-- /底部区域 -->

    <!-- 发布评论 -->
    <van-popup 
      v-model="isPostShow" 
      position="bottom"  
    >
      <post-comment :target="articleId" @post-success="onPostSuccess"/>
    </van-popup>
    <!-- /发布评论 -->

    <!-- 评论回复 -->
    <van-popup
      v-model="isReplyShow"
      position="bottom"
    >
      <!--这里使用v-if 的目的是让组件随着弹出层的显示进行渲染和销毁，防止加载过的组件不重新渲染导致数据不会重新加载的问题-->
      <comment-reply v-if="isReplyShow" :comment="replyComment" :article-id="articleId" @close="isReplyShow=false"/>
    </van-popup>
    <!-- /评论回复 -->

  </div>
</template>

<script>
import  './github-markdown.css'
import { getArticleById,addCollect,deleteCollect,addLike,deleteLike } from '@/api/article'
import { ImagePreview } from 'vant';
import { addFollow, deleteFollow } from '@/api/user'
import CommentList from './components/comment-list.vue'
import PostComment from './components/post-comment.vue'
import CommentReply from './components/comment-reply.vue'


export default {
  name: 'ArticleIndex',
  components: {
    CommentList,PostComment,CommentReply
  },
  //在组件中获取动态路由参数：
  //  方式一：this.$route.params.articleId
  //  方式二：props传参，推荐
  //         this.articleId
  props: {
    articleId: {
      type: [String,Number,Object],
      required: true
    }
  },
  data () {
    return {
      article: {},//文章详情
      isFollowLoading: false, //关注用户按钮的loading状态
      isCollectLoading: false, //收藏按钮的loading状态
      isPostShow: false, //控制发布评论的显示状态
      commentList: [], //文件评论列表
      totalCommentCount: 0, //评论总数据
      isReplyShow: false, ///控制回复的显示状态
      replyComment: {}, //当前回复评论对象
    }
  },
  computed: {},
  watch: {},
  created () {
    this.loadArticle()
  },
  mounted () {},
  methods: {
    async loadArticle () {     
      const { data } = await getArticleById(this.articleId)
      //console.log(data);
      this.article = data.data

      
      
      //数据改变影响视图更新（DOM数据）不是立即的
      //所以如果需要在修改数据之后马上操作被该数据影响的视图 DOM，
      //需要把这个代码放到 $nextTick中
      
      this.$nextTick(()=>{
        this.handlePerviewImage()
      })
      //循环img列表，给img 注册点击事件
      //在事件处理函数中调用ImagePreview()预览

    },
    handlePerviewImage () {
      //1.获取文章内容DOM容器
      const articleContent = this.$refs['article-content']
      //2.得到所有的img标签
      const imgs = articleContent.querySelectorAll('img')
      //console.log(imgs);
      const imgPaths=[]
      //3.循环img列表，给img注册点击事件
      imgs.forEach((img,index) => {
        imgPaths.push(img.src)
        img.onclick = function () {
          //4.在事件处理函数中调用ImagePreview()概览
          ImagePreview({
            images:imgPaths, //预览图片路径列表
            startPosition:index //起始位置
          })
        }
      });
    },
    async onFollow () {
      // 开启按钮的 loading 状态
      this.isFollowLoading = true

      if (this.article.is_followed) {
        // 如果已关注，则取消关注
        await deleteFollow(this.article.aut_id)
      } else {
        // 否则添加关注
        await addFollow(this.article.aut_id)
      }
      this.article.is_followed = !this.article.is_followed
      // 关闭按钮的 loading 状态
      this.isFollowLoading = false
    },
    async onCollect () {
      this.$toast.loading({
        message: '操作中...',
        forbidClick: true //禁止背景点击
      })
      if (this.article.is_collected) {
        // 如果已关注，则取消关注
        await deleteCollect(this.articleId)
      } else {
        // 否则添加关注
        await addCollect(this.articleId)
      }
      this.article.is_collected = !this.article.is_collected
      // 关闭按钮的 loading 状态
      this.isCollectLoading = false
      this.$toast.success(`${this.article.is_collected ? '' : '取消'}收藏成功`)
    },
    async onLike () {
      // 两个作用：1、交互提示 2、防止网络慢用户连续不断的点击按钮请求
      this.$toast.loading({
        //duration: 0, // 持续展示 toast
        message: '操作中...',
        forbidClick: true // 是否禁止背景点击
      })

      // 如果已经点赞，则取消点赞
      if (this.article.attitude === 1) {
        await deleteLike(this.articleId)
        this.article.attitude = -1
        this.$toast.success('取消成功')
      } else {
        // 否则添加点赞
        await addLike(this.articleId)
        this.article.attitude = 1
        this.$toast.success('点赞成功')
      }
      //this.$toast.success(`${this.article.attitude ? '' : '取消'}点赞成功`)
    },
    onPostSuccess(comment){
      //把发布成功的评论数据对象放到评论列表顶部
      this.commentList.unshift(comment)

      //更新评论的总数量
      this.totalCommentCount++

      //关闭发布评论弹出层
      this.isPostShow = false
    },
    onReplyClick (comment) {
      //console.log('onReplyClick',comment);
      this.replyComment = comment

      //展示回复内容
      this.isReplyShow=true
      // console.log(this.isReplyShow);
    }
  }
}
</script>

<style scoped lang="less">
.article-wrap {
  position: fixed;
  left: 0;
  right: 0;
  top: 46px;
  bottom: 44px;
  overflow-y: auto;
}
.title {
  font-size: 20px;
  color: #3a3a3a;
  padding: 14px;
  background-color: #ffff;
  margin: 0;
}
.user-info {
  .avatar {
    width: 35px;
    height: 35px;
    margin-right: 8px;
  }
  .name {
    font-size: 12px;
    color: #333333;
  }
  .pubdate {
    font-size: 11px;
    color: #b4b4b4
  }
  .follow-btn {
    width: 85px;
    height: 29px;
  }
}
.markdown-body {
  padding: 14px;
  background-color: #fff;
}
.article-bottom {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  justify-content: space-around;
  align-items: center;
  box-sizing: border-box;
  height: 44px;
  border-top: 1px solid #d8d8d8;
  background-color: #fff;
  .comment-btn {
    width: 141px;
    height: 23px;
    border: 1px solid #eeeeee;
    font-size: 15px;
    line-height: 23px;
    color: #a7a7a7;
  }
  .van-icon {
    font-size: 20px;
    .van-info {
      font-size: 11px;
      background-color: #e22829;
    }
  }
}
</style>